Sunspots

If you look up into a cloudless night sky, away from city lights, you'll see thousands of stars. We know quite a lot about those stars, but there's only one - our Sun - that we can take detailed pictures of. We, Keith and Andrew, are going to tell you about some dark blotches, called sunspots, which are seen in photos of the Sun.

This picture was taken by an instrument on board the SOHO spacecraft and shows the Sun much as it would appear with an 'ordinary' camera.

In this kind of picture we see the Sun's "yellow surface" (called the photosphere) and “dark blotches” (called sunspots)

Those sunspots may not look very interesting at first glance, but the amazing thing is that they can tell us a lot about the Sun.

Here's a movie of some sunspots on the surface of the Sun. See how large they are compared to the Earth.

The largest sunspots can last for weeks, but small spots can form and disappear again in just a few hours.

The red filter shows the appearance of the Sun in the light emitted by hydrogen atoms. By looking at this particular colour of light, it is possible to see the structure around sunspots just above the solar surface.